Ball-point writing instrument



Nov. 24, 1553 R. w. RANDOLPH BALL-POINT WRITING INSTRUMENT Filed Aug. 13, 1945 IN V EN TOR. @0558? W. E/M/DOLP/l A TTORNEYS.

Patented Nov. 24, 1953 BALL-POINT WRITING INSTRUMENT Robert W. Randolph, Milton, Wis., assignor to The Parker Pen Company, Janesville, Wis., a corporation of Wisconsin Application August/13, 1945, Serial No. 610,423

This invention relates to ball-point writing instruments and has for its principal object to provide an inexpensive but none-the-less reliable device of that character having a readily replaceable self-contained refill unit comprising an ink holding reservoir and a ball-point writing tip, which unit, when replaced, affords not only replenishment of the ink supply but, in addition, a new writing tip.

Another object is to provide an instrument of the aforementioned character so constructed that the refill unit can be removed and replaced quickly and easily, without the exercise of any special skill.

A further object is to devise a ball-point writing instrument wherein the refill unit is of such simple design that it can be manufactured to sell at a low price without any sacrifice of essential quality, thus keeping the cost of maintenance at a minimum while at the same time insuring continuously dependable performance.

Additional objects and advantages will become apparent from the detailed description to follow.

One of the features characterizing this invention resides in the extreme simplicity of the refill unit, which can be made by a simple forming operation upon a single piece of straight thinwalled metal tubing and is capable of being produced so economically as to bring down the cost of replacing the unit to such an extentthat refilling the ink reservoir can hardly be justifiedespecially in view of the fact that the ink supply afforded by a single unit usually is sufficient for many months of service, and of the further fact that replacing the unit provides a new writing point and thus insures that the instrument will remain continuously in good working order.

Another characterizing feature of considerable importance resides in the simple and inexpensive but nevertheless effective means by which the ball-and-cartridge unit is retained in the holder while at the same time its vented end is auto matically sealed against ink leakage and will remain so sealed irrespective of vibration or careless handling. This feature entails the use of a simple resilient bushing made of soft rubber or other suitable like material and having an axial bore designed to embrace snugly the back end portion of the ball-and-cartridge unit while at the same time permitting the latter to enter without difiiculty whenever a replacement is required. This feature also is one which contributes substantially to the objective of low price coupled with high quality and, furthermore, is one which would be completely satisfactory even 2 Claims. (Cl. 120-42. 1) v .2 for use in ball-point writing instruments designed to sell at much higher prices.

Referring to the drawing:

Fig. 1 is a longitudinal sectional view of a ballpoint writing instrument constructed in accordance with this invention;

Fig. 2 is an elevational view of a self-contained refill unit comprising an ink cartridge and ball point;

Fig. 3 is a cross-sectional view taken along line 3-3 of Fig. l; and

Fig. 4 is a cross-sectional'view taken along line 4-4 of Fig. l.

The structure illustrated comprises a holder I which includes an elongate tubular barrel 2 tapered externally at the front or writing end, as shown, and having an axial bore extending throughout its length, the forward portion of which is proportioned to slidably fit, the replaceable ball-and-cartridge refill unit 3, shown separately in Fig. 2. The bore of barrel 2 is enlarged at d and internally threaded at 5 to engage the threaded lower end of a tubular sleeve 6, the function of which is to provide means for detachably securing to the barrel a removable cap 1', which is manually withdrawable from sleeve 6, and thus from barrel 2, simply by applying a small amount of separating force axiswise. It will be observed that cap 7 is telescoped over sleeve 6 and is frictionally engaged therewith. Barrel 2 may be of metal or plastic material, and the same is true of sleeve 6 and cap l.

Mounted within and attached to the upper end of cap 1 is a depending tubular member 8, me ternally threaded at its upper end to receive a screw 9 which serves to fasten member 8 to cap 1. Screw 9 may form part of a pocket clip or its mounting, not shown.

Secured within the main bore of member 8 is a bushing of resilient material. This may be composed of soft rubber or sponge rubber or any other suitable material which is suiilciently resilient to permit insertion of the upper end portion of unit 3 while at the same time being capable of grip-ping said unit and retaining it in place until it is intentionally withdrawn. Bushing it also functions as an effective seal against ink leakage into the interior of the barrel 2 from the rear end of the ball-and-cartridge unitwhich latter must be open in order to vent the ink reservoir to atmospheric pressure. This simple device for anchoring the unit in place while at the same time sealing against ink leakage constitutes an important feature of the invention. It is highly effective and dependable while at the same time being quite inexpensive.

The ball-and-cartridge unit 3 is of exceedingly simple construction-which is a cardinal advantagebeing made from a thin-walled metal tube and formed at its lower end to provide a seat and retainer for a ball I I, which latter constitutes the writing point of the instrument. The bore of the tube above ball [I constitutes an ink cartridge or reservoir and is filledwith a viscuous paste-like ink which will not leak past said ball under the force of gravity, but will adhere thereto and thus be transferred in unform minute quantities to the writing surface as the ball rolls tn'ereover.

The upper end of the ball-and-cartridge unit must be closed to seal in the ink prior to the time when the unit is put to use, and one satisfactory way in which this can be done is to thread the upper end of the unit and attacha screw cap 12-; which is removable just before the unit is to be inserted into the holder. Alternatively, the upper end of the unit can be closed by means of a perforable seal designed tobe pierced just before the unit is installed.

Preferably, but not necessarily, the lower end of the ball-and-car'tridge unit is of slightly larger diameter than the remainder thereof so that said lower end will not enter the bore of barrel '2.

Removal of the unit, when replacement is necessary, usually is accomplished by withdraw-'- ing cap 7 from sleeve, Band allowing the unit to drop out. It will be apparent thatwhen cap 1 is removed the upper end of the unit is automatically withdrawn from bushing Ill. Obviously, the unit. can be withdrawn from the holder by simply gripping the lower end thereof and, applying tension axially, without then'ecessity of removing cap 1. Therefore, it. would be entirel feasible and within the purview. of. this invention to permanently attach cap I to the barrel. In. such event, the replacement unit would beinserted in the barrel bore as before, and'would enter bushing ID as a matter of. course.

In order to insure that the ink in the reservoir will continue to feed down as required, it is necessar to vent the upper end thereof to the atmosphere, andthis conveniently can be accomplished be providing a small venting aperture l3 which communicates. with the open end of the cartridge via a recess M in member 8. The. diameter of aperture [3 may be ofthe order of .020." and, in

any event, should be small in diameter and long enough to prevent leakage of ink therethrough.

To install a fresh ball-and-cartridge unit the latter shouldv be held in a vertical positionv with ball H resting on.a suitable; supporting surface, preferably with an intervening blotter. to prevent marking said surface. Screw cap [2: is then removed and the barrel slipped down over. the; unit until it bottoms on the shoulder l5, as shown in Fig. 1. Cap 1 is then put on and this inherently results in the upper end of the unit entering the bore of bushing 10 by means of which itis retained until another replacement is required.

While it is preferable so to enlarge the lower end of the unit that it cannot enter the bore of barrel 2, such precaution is by no means an indispensable one. But so-long as there is retained the construction illustrated, wherein cap 1 isseparable from the barrel by merely pulling it therefrom axiswise, it manifestly is advisable so to form the unit that the lower end portion thereof cannot enter the barrel. Onthe contrary, cap I were undetachable or so secured in place that it would not yield to-a mere axiswise pull, it would be feasible to make the unit of such diameter throughout that even. the ball end could enter the barrel, were it not for the fact that there is a stop at the upper end to prevent its doing so.

It will be self-evident from mere inspection of the drawing that the component parts of the illustrated writing instrument are few in number and of exceedingly simple design, all of which is contributive to low-cost manufacture; while at the same time the instrument obviously is devoid of factors likely to bring about premature failure. Moreover, it will be apparent that the ball-andcartridge unit, per se, is of such simple construction as to enable refills to be sold at a low price, thus rendering it economical to replace the entire unit, thereby. obtaining a new writing point each time the ink supply. is replenished, as against the alternative procedure of merely refilling the empty unit.

Another feature which is worthy of mention is that in putting in a refill unit there is little likelihood of getting ink on ones fingers, provided ordinary care is exercised. Moreover, there is no probability of ink escaping from the unit and soiling the inside of the barrel since the bushing It) serves as a very efficient seal, and said bushing eifectively wipes off the upper end of the unit as the latter is being withdrawn, thus forestalling the possibility of residualink finding its way into the bore of the barrel and thence to the exterior surface of the instrument.

The ball-and-cartridge unit, per se, as shown in Fig. 2 is an operative writing instrument, independently of the holder, and can be kept continuously operative until the ink supply is exhausted by occasionally loosening screw cap l2, thus admitting atmospheric air to onset. the reduction of internal pressure which results from lowering of theink level;

I claim: I

1.. In a. ball-point writing. instrument, aholder com rising a barrel open at both ends, a cap removably attached to and closing the rearward end of said barrel, abutment means on said barrel for seating said cap in position closing the rearward end of the barrel, an elongate balland-cartridge unit including a straight, rigid tube having a writing ball at its forward end, the portion of said tube rearwardly ofsaid ball freely and easily slidable in. said barrel and providing asingle ink reservoir with an unobstructed interior and having a vent inits rearward portion, said barrel having an axial bore, slidably accom modating said unit, and means carried by said cap for releasably gripping the end portion of said. unit. at a point. remote from. said writing ball and displacedfrom said vent and effective to retain said unit in. said holder but releasable from. said. unit to permit withdrawal thereof from the holder, said means being the solemeans for retaining said unit in said holder.

2, In a ball-point writing instrument, a renewable ball-and-cartridge unit comprising a straight, rigid, elongate tube openat both ends and provided at one end with a writingball and means forseating and attaching the same to the tube while permitting rotation thereof, said attaching means including a rigid ball seat and a peripherally continuous cup shaped portion surrounding the rearward portion of the ball, the interior of said tube behind said ball seating means providing a single unobstructed ink reservoir' space of substantially uniform diameter in communication with said ball, an elongatehold'er for said unit comprising a barrel portion having a bore opening at the front end thereof and a cap removably attached to the back end of said barrel and positively seated thereon in a single predetermined, normally fixed position closing said back end, said cap and barrel being co-axial, a resilient bushing carried by and within said cap and having a bore in axial alignment with the bore of said barrel and proportioned to slidably and grippingly receive the rearward end portion of said unit for yieldably retaining the same in said holder, said unit being forcibly withdrawable from said bushing from the front end of said holder.

ROBERT W. RANDOLPH.

References Cited in the file of this patent v UNITED STATES PATENTS Number Name Date 338,611 Pusey Mar. 23, 1886 Number 15 Number Name Date Caruso May 17, 1887 Fessenden Mar. 3, 1896 Brenton May 7, 1907 Mussinan Aug. 6, 1907 Riesberg Feb. 15, 1916 Chapman Jan. 28, 1930 Schweiger June 23, 1931 Vessey Nov. 14, 1933 Biro Dec. 11, 1945 Biro Mar. 4, 1947 Chesler June 22, 1948 FOREIGN PATENTS Country Date Switzerland Oct. 16, 1942 

